have this 365 running ruff have to codes 577 and 578 cylinder balance cylinder 7 and 8 now when its idling its making a horrible sound i never heard before sounds as if u can hear the cylinder firing threw the intake tube or the air filter opening i am thinking a broken valve spring or rocker any ideas

Take top off and look for buttons broke off the rockers. Sometimes you can find these stuck to drain plug. But most likely you have a roller on lifter broke, turned sideways and really messed up cam shaft. Bad enough and ran long enough, you may be looking at new motor.

took valve cover off found rocker arm tip broken of got a new one but the clearance was way off took oil pump off to see lifter and sure enough the roller was gone and the lifter distoyed the cam I will be pullin the motor tomarrow o joy........